Well tools



United States Patent References Cited UNITED STATES PATENTS DeinestBryant.... Cummings. Baby Kramer... Kau1ins.... Dickens PrimaryExaminerWi1liam F. O'Dea Assistant Examiner-Howard M. Cohn Attorneys-E.Hastings Ackley and Walter J. Jagmin 137/614.2 137/614.2X 251/75X137/614.2X 137/614.2 137/460 137/460 ABSTRACT: This invention relates toa fluid flow control device comprising a safety va1ve and a check valveincluding a bypass around the check valve to permit displacement of anyfluid which may become trapped between the valves and prevent opening ofthe safety va1ve.

Patented Dec. 1, 1970 INVENTOR Wi ll|0m W. Dollison wwm WELL TOOLS Thisapplication is a continuation-in-part of the copending application Ser.No. 328,l57, filed Nov. 29, 1963, now abandoned.

This invention relates to well tools and more particularly to a flowcontrol device for controlling the flow of fluids through a flowconductor, such as well tubing.

One object of this invention is to provide a new and improved controldevice for use in a well flow conductor which is responsive to fluidpressure within the conductor for controlling the flow of fluidstherethrough.

Another object of the invention is to provide a new and improved valvefor a flow conductor wherein the valve is responsive to a predeterminedrate of flow of fluid within the conductor for controlling the flow offluids therethrough.

A further object of the invention is to provide a new and improvedpressure responsive device for controlling the flow of fluids through afluid conductor including a valve mechanism wherein the valve isprevented from assuming any position between its fully opened and fullyclosed positions to preclude erosion or abrading of the valve parts bythrottling the fluid stream or by making its path more tortuous.

An additional object of the invention is to provide a detent mechanismfor a valve which controls the flow of fluids through a tubing or thelike wherein the detent mechanism will hold the valve in fully openedposition until a force of predetermined magnitude is exerted on thevalve by the flow of fluids through the tubing to release the detentmechanism and move the valve to fully closed position.

It is another object of the invention to provide a detent mechanism fora valve adapted to control the flow of fluids through a tubing or thelike wherein the detent mechanism will detain the valve in fully openedposition and resist its being closed by temporary surges of fluid flowthrough the tubing.

It is a further object of the invention to provide a detent mechanismfor use in a well tubing valve to detain the movement of the valve to aclosed position until sufficient energy has been built up to move thevalve to fully closed position upon release of the detent mechanism,such detent mechanism utilizing ball-type locking elements whichminimize the frictional forces between the valve members engaged .by themechanism and which move relative to each other upon release ofthemechanism.

It is a further object of the invention to provide a tubing safety valveemploying a ball-type valve element biased to an open position by aspring and further utilizing a spring loaded detent mechanism adapted toretain the valve element in open position until the load resulting fromfluid flow through the tubing is of a predetermined magnitude in excessof the force required to depress the valve element biasing spring.

It is a still further object of the invention to provide a fluid flowcontrol device for use in a conductor such as a well tubing wherein asafety valve having a detent mechanism associated therewith is combinedwith a fluid check valve.

It is another object of the invention to provide a fluid flow controldevice comprising a safety valve and a check valve including a bypassaround the check valve to permit displacement of any fluid which maybecome trapped between the valves and prevent opening of the safetyvalve.

It is a still further object of the invention to provide a combined welltubing safety and check valve utilizing ball-type valve elements foreffecting boththe safety and check valve functions and a spring loadedball-type detent mechanism in association with the safety valve.

It is another object of the invention to provide a check valve assemblyhaving means for biasing the valve toward open position.

Additional objects and advantages of the invention will be readilyapparent from the reading of the following description of a deviceconstructed in accordance with the invention, and reference to theaccompanying drawings thereof, wherein:

FIG. 1 is a longitudinal view partially in section and partially inelevation ofa well tool in accordance with the invention illustratingboth the safety valve and the check valve in full open positions;

FIG. 2 is a longitudinal view of the well tool partially in section andpartially in elevation illustrating the safety valve in a fully closedposition and the check valve assembly in a partially open position;

FIG. 3 is a view in section along the line 3-3 of FIG. I showing thesafety valve in a full open position to allow fluid flow through thetubing; and,

FIG. 4 is a view partially in elevation and partially in section of thelower end of the well tool at a stage in its operation when the safetyvalve is beginning to open and the check valve is fully closed.

Referring to FIG. 1, a well tool 10 constructed in accordance with theinvention is supported on a tubing string 11 to control fluid flowthrough the tubing string. The well tool includes a safety valveassembly 12, a detent mechanism 13 operatively associated with thesafety valve assembly for detaining the safety valve in open positionuntil a predetermined force is exerted on the valve. and a check valveassembly 14 which includes a spring unit 15 to prevent full closure ofthe check valve until a predetermined force is exerted on the valve. Atop sub 20 which is internally threaded at 21 is engaged on the lowerend of the tubing string. The top sub is externally threaded at 22 andis provided with an internal annular recess 23 in which a packingassembly 24 is positioned. An upper housing member 25 is internallythreaded at 30 to permit its engagement with the lower end of the topsub and externally threaded at 31 to support the lower housing member32. The lower housing member is internally threaded at 33 for engagementwith the lower end of the upper housing rnember..The lower housingmember is internally at 34 for en' gagement with the bottom sub 35 whichis externally threaded at 40.

A safety valve seat body 41 is slidably positioned within the housingwith the packing assembly 24 forming a substantially fluid tight sealaround the seat body within the top sub. An annular-shaped spacer ring42 is disposed around the seat body with the upper face of the spacerring engaging the lower end of the top sub. A lock ring 43 is securedaround the seat member in a shallow annular recess 43a in the seat body41 to support the lower end of a spring 44 which is confined between thelock ring and the spacer ring 42 to provide a downward bias to the body.The valve seat body is provided with an internal bore 45 to allow fluidflow therethrough. A flow bean 50 with a bore 50a is secured within thelower portion ofthe seat body. The flow bean is held in the body againstdownward movement by a retaining ring 51 which is engaged in an annularrecess 52 formed within the body. Upward movement of the flow bean isprevented by engagement of the external annular shoulder 50b on the flowbean with the internal annular shoulder 500 within the valve seat body.Above the slot 52 the body is provided with an internal annular recess53 in which an O-ring 54 is positioned to form a seal between the flowbean and the body. The lower end of the body is provided with a conicalvalve seat surface 55. Annular external flanges 60 and 61 are formedaround the lower portion of the valve seat body spaced apart from eachother to provide an annular recess 62 around the body. The annularflange 61 is provided with two longitudinally extending slots 63 locatedon opposite sides of the, valve seat body. While only one of the slots63 is visible in FIG. 1 it is to be understood that an identical slot isformed in the back side of the body so that the slots will be spacedapart The T-shaped ball valve support members 64 are engaged on oppositesides of the safety valve seat body with the lateral portions 640 of thesupport members being positioned within the annular recess 62 and thelongitudinal portions 64b of the support members extending downwardlythrough the slots 63. Referring to FIGS. I and 3, each of the arms 64 isprovided with an inwardly projecting pin 65. The pins 65 cooperate toprovide pivotal support for the ball valve 70.

The ball valve 70 is provided with a cylindrical bore 71 which whenalined with the bore of the safety valve seat body, as shown in FIG. 1,permits fluid flow through the safety valve assembly. The flat surfacesor faces 7 2 are formed on opposite sides of the ball valve, see FIG. 3,in planes which extend parallel to each other and parallel to the axisof the bore 71 through the valve element. A blind hole recess 74 isformed at the center of each of the flat surfaces 12 of the ball valveto receive the pins 65 for supporting the ball valve from the safetyvalve seat body. The ball valve is provided with the'slots 80 which areformed in the valve opening into the faces 72. The centerline of each ofthe slots 80 extends through the center of the recess 65 at an anglewith the axis of thebore 71. The pins 82 are secured through oppositesides of the lower housing member 32 extending into 'the slots 80. The:slots 80 are so located with respect to. the recesses 74 that the ballvalve rotated by longitudinal movement of the pins 65 relative to thepins 82. Since the ball valve is pivotally supported on the pins 65,upward and downward movement of the pins by raising and lowering thearms 64 raises and lowers the ball valve relative to the pins causingthe fixed pins to slide in the slots to rotate the ball valve about itsaxis. The pins 84 are secured through opposite sides of the housingmember 32, as shown in FlG..3, sothat the inward ends of the pins, eachof which is flat, may cooperate with the faces 72 to aid in maintainingthe alinement of the ball valve as it rotates. Each pin 84 is spacedapart from a pin 82 a distance which permits a ball valve support arm 64to extend between the pins to guide and maintain the longitudinalalinement of the support arms.

The lower housing member 32 is provided with an internal annular flange90 having an upper, downwardly and inwardly sloping face 900 and a lowerupwardly and inwardly sloping face 90bfThe face 900 functions to limitthe downward movement of the safety ball valve 70 as the ball valveengages and is supported by the face of the flange when the valve is infull open position, as illustrated in FIG. 1. The lower face 901) of theflange performs a similar function with respect to limiting upwardmovement 'of the check valve, as willbe explained hereinafter. 1 I

:Tlie detent assembly l3-is operativ'ely engaged between the upperhousing member 25 and the safety valve seat body 41. The upper housingmember is provided with an internal annular flange 91 forming within thehousing a downwardly facing shoulder 92. Below the shoulder 92 aninternal'annular recess 93 is formed adjacent to the lower end of theupper housing member. The valve seat body 41 is provided with anexternal annular recess 94. An annular cage or ring 95 is positionedaround the valve seat body within the upper housing member. The cage isprovided with a plurality of radially spaced apertures 100 toaccommodate the balls 101. An annular spacer ring 102 is positionedaround the valve seat body engaging the upper end of the cage 95. A coilspring 103 is confined between the shoulder 92 and the upper end of thespacer ring 102 around the valve seat body. The distance betweenexternal surface of the body 41 from the ring 43 to the flange 60 andthe internal surface of the housing member'25 below the flange 91 isless than the diameter of the balls 101 thus requiring that the'ballsengage either or both of the recesses 94 and 93. The depth of either ofthe recesses plus the distancg between the valve seat body and thehousing member below the shoulder 92 is substantially equal to. thediameter of the balls. The relative vertical positioning of, therecesses 93 and 94 is such that when the safety valve is in openposition, as illustrated in FIG. 1, the recess 93 will be sufficientlyabove the recess 94 that the balls 101 will engage the recess 94 in theseat body while contacting the inner surface of the upper housing memberimmediately below the recess 93. When the valve is positioned as shownin FIG. 2 the balls 101 engage the recess 93 while contacting theexternal surface of the upper valve seat member below the recess 94. Thespring 103 acting through the spacer ring 102 biases the. cage and ballsin a downward direction. Upward movement of the safety valve assemblycompresses the spring 103 to disengage the detent assembly in a mannerwhich will be explained in more detail hereinafter in the discussion ofthe operation of the well tool of the invention.

The check valve assembly 14 is engaged within the lower housing member32 so that the check valve will remain in open position, as shown inFIG. 1. while upward fluid flow is occurring through the tubing string,but when flow stops the,

valve closes as in FIG. 2 and with downflow moves to the position ofFIG. 4. Check valve seat body 110 is a tubular-shaped member having alongitudinal bore 111 to permit fluid flow therethrough. The upper endof the check valve seat is an inwardly facing spherical face 112providing a valve seat for the ball check valve. Near the upper end ofthe check valve seat body an annular external recess 113 is formedaround the member. Below the recess 1 13 the seat body is reduced inexternal diameter to provide a downwardly facing shoulder 114. The valveseat body is further reduced in diameter at 115 at the seat body withinthe sub. The other external dimensions of the seat body are such thatfluid may flow from between the two valves around the seatbody. A colletring 123 having upwardly extending fingers 124 provided with inwardlyprojecting bosses 125 is engaged around the valve seat body with thebosses 125 engaging the flange 120 to provide longitudinal I support forthe collet ring. A coil spring 130 is positioned around the seat memberconfined between the shoulder 114 and the collet ring.

The T-shaped ball check valve support arms 131 are engaged on oppositesides of the check valve seat body 110. The

arms 131 are identical in shape and function to the arms 64 git udinalportion 1310 of each arm extends through a longituwhich support the ballsafety valve. The arms 131 each comprises a long tudinal extendingportion 131a and a lateral portion 131b which is engaged in the annularrecess 113. The londinally oriented recess 132 formed in the valve seatbody above the recess 113. A recess 132 is formed on each side of thebody to accommodate the oppositely positioned arms 131.

Each of the arms 131 is provided with an inwardly projecting valve. Ineach of the faces 141 a slot 142 is formed to receive I the pins 143.which are secured to and through the lower housing member extendinginto the slots. Also secured through the lower housing member are thepins 144, the inward ends of which engage the flat surface 140 toprevent the ball check valve from rotating about the longitudinal axisof the housing member as the check valve is moved between open andclosed positions. Upward and downward movement of the seat member 110causes the ball check valve to be raised and lowered within the housingmember and since the pins 143 are fixed through the housing member toengage the slots 142 the pins remain in a stationary position as thevalve is raised and lowered causing the valve to rotate about the pins133. As illustrated in FIG. 1, when the valve is up in fully openposition the ball valve engages the downwardly facing surface b withinthe housing member. In addition to the pins 143 cooperating with theslots 142 to rotate the ball check valve, the pins 143 along with thepins 144 serve as guides for the portions 131a of the arms 131 as thearms are raised and lowered with the check valve body.

The well tool is employed to control the flow of fluids from a wellbore. The tool is secured by the threads '21 to the tubing string 11which is introduced into the well bore with the tool being positioned atthe desired level. The well tool controls the flow of the well fluidthrough the tubing string 11 shutting off flow when the pressuredifferential across the safety valve assembly exceeds a predeterminedvalue. When the tool is positioned in the tubing string and before fluidflow occurs, the safety valve will be in open position and the checkvalve in closed position. Since at this stage the valves at the top ofthe well will be closed, no pressure differential will exist across thevalves of the tool. The coil spring 44 around the safety valve seat body41 acting against the lock ring 43 biases the safety valve seat bodydownwardly so that the safety valve 70 is in open position resting onthe face 900 of the lower housing member 32. Since the safety valve issupported on the arms 64 which are engaged on the valve seat body, thepins 65 on the arms are located, as illustrated in FIG. 1, at a levelbelow the fixed pins 82 which extend through the lower housing member.The detent mechanism 13 is engaged with the safety valve assembly. Therecess 94 is at a level slightly below the recess 93. The balls 101 arebiased downwardly by the coil spring 103 and are cammed inwardly by thelower face of the recess 93 so that the balls engage the recess 94 inthe safety valve seat body thus applying the downward bias of the coilspring 103 to the valve seat body. The balls 101 contact the inner wallof the upper housing member 25 immediately below the internal annularrecess 93 within the upper housing member. Thus, the ball safety valveis held in open position by both the coil spring 44 and by the detentassembly spring 103.

When the well tool is initially installed in the well bore, the surfacevalves are closed and no flow is occurring through the tool. The ballcheck valve 134 will, since no pressure differential exists across thevalve assembly, assume the position illustrated in FIG. 2 as the weightof the assembly will cause the valve seat body to drop downwardly untilthe body is supported by the coil spring 130 pressing against the colletring 123. The downward pull of the arms 131 and thus the pins 133 willhold the check valve in the position illustrated since the pins 133 pullthe ball check valve downwardly relative to the pins 143 which act inthe slots 142 to rotate the check valve to the closed position. Thespring 130 together with the collet mechanism keep the check valve seatslightly upward separating the surfaces 121 and 122 to allow slightfluid flow around the check valve body for purposes which will beexplained. Thus, when the well tool is positioned within the well boreand before fluid is allowed to flow through it, the safety valve will bein the open position illustrated in FIG. 1 while the check valve will bein the partially closed position illustrated in the lower portion ofFIG. 2.

Upon completion of the positioning of the well too] in the well bore thenecessary valves at the surface are opened to allow fluid flow throughthe well tool. The lower pressure at the surface due to opening thevalves creates a pressure differential across the check valve assembly,both across the valve seat and the ball check valve. The pressuredifferential initiates upward movement of the check valve pushing it tothe open position, illustrated in FIG. 1. Upward movement of the body110 carries the arms 131 upwardly and thus the pins 133 supporting theball check valve move upwardly relative to the pins 143 which slide inthe slots 142 of the ball check valve. The pins 143 cause the ball checkvalve to revolve about its axis to the open position illustrated. Afterthe ball check valve is open, the pressure differential across the valveseat and the ball check valve will hold the valve assembly in openposition. So long as fluid flow through the well tool remains withinpredetermined safe limits the various parts of the tool will bepositioned, as illustrated in FIG. 1, with both the safety valve and thecheck valve in open positions due to the pressure differentials effectedacross the elements, The fluid flows into the bottom sub, through thebore 111 of the check valve seat body, through the bores 135 and 71 ofthe check valve and safety valve, respectively, through the bore 50a ofthe flow bean into the bore 45, and then into the tubing string 11.

When the pressure within the well bore below the well tool exceeds whathas been established as a safe limit the pressure differential acrossthe flow bean will effect closure of the ball safety valve. The flow offluids through the bore 57a of the flow bean 50 produces a pressure dropacross the bean. The differential pressure acts upwardly against an areasealed by the packing 24 exclusive of the area of the bore 500 with thepressure differential tending to lift the flow bean along with the othermembers of the safety valve assembly including the seat body 41 and theball safety valve 70. The lifting force exerted against the safety valveassembly is opposed by the biasing force of the coil spring 103 in thedetent assembly. When the difference in pressure across the flow beanexceeds the predetermined value necessary to overcome the resistance ofthe coil spring of the detent assembly, the lower surface of the recess94 in the safety valve seat body lifts the balls 101 which raises thecage and spacer to depress the spring. When the balls have been lifted ashort distance they are opposite the recess 93 within the upper housingmember 25 and since the seat body is being urged upwardly the balls arecammed into the recess 93 by the outwardly facing lower surface of therecess 94 resulting in the complete disengagement of the safety valveseat body from the detent mechanism to free the body to be raised by thepressure differential. As the body is raised the arms 64 along with thepins 65 are lifted relative to the pins 82 which remain in their fixedlocations through the lower housing member. As the pins 65 are liftedthe safety valve which is pivotally supported on the pins is rotated bythe action of the pins 82 in the slots 80 until when the seat body is atits uppermost position the ball safety valve is fully closed, asillustrated in FIG. 2. The pins 84 cooperate with the surfaces 72 tolimit rotation of the valve to the axis through the pins 65. Therefore,any twisting motion of the safety valve is precluded. When the safetyvalve is in closed position the surface of the valve engaged with theseat 55 seals off fluid flow through the well tool. The pressure withinthe tool below the safety valve maintains the surface of the valve insealing engagement with the seat.

Once the detent assembly is disengaged from the valve seat body theclosing of the ball safety valve is effected quickly and positivelywithout the normal lingering and resultant throttling effect from aconventional type slow closing valve. The downward bias of the detentassembly is normally slightly greater than the force needed to depressthe spring 44 so sufficiently to close the safety valve so that thedetent assembly spring must first be compressed and the detent assemblydisengaged before the safety valve may be moved to closed position. Forexample, the safety valve seat body may have to move upwardlythree-quarters of an inch to close and if the spring 44 is initiallyloaded to 300 pounds and requires an additional pounds per inch todepress it, the load of the spring when depressed three-quarters of aninch will be about 356 pounds. A coil spring 103 is chosen whichrequires a load slightly in excess of the additional load needed todepress the spring 44, about 58 pounds, to disengage the detentmechanism from the safety valve seat body. Thus, it is necessary that anupward force of at least 358 pounds be exerted against the safety valveassembly to disengage the detent mechanism to allow the assembly to beurged in an upward direction against the force of the spring 44. Sincethe spring 44 may be depressed the required distance by a force of about56 pounds in excess of the load on the spring and an excess force of 58pounds is exerted against the assembly to disengage the detentmechanism, the safety valve is fully and completely closed withoutlingering or chattering once the detent mechanism is disengaged. Sincethe force necessary to depress the coil spring of the detent assemblyand thus disengage the assembly is greater than the force required todepress the coil spring 44 to the extent necessary to effect closing ofthe safety valve, the larger force being exerted upon the valve seatbody immediately moves the valve seat body upwardly a sufficientdistance to fully close the safety valve after the detent assemblyisdisengaged. In other words, when the detent assembly is disengaged,enough energy is available and is being exerted upon the safety valveseat body to quickly and fully close the ball safety valve. It isunnecessary, therefore, to gradually build up the force required tofully close the valve and therefore the slow throttling effect resultingin the conventional type of safety valve not utilizing such a detentmechanism is avoided.

When the safety valve has been rotated to the closed position thepressure differential across the check valve and the valve seat 1 10equalizes and the check valve closes due to the force of gravityupon'the check valve assembly. The weight of the various memberscomprising the check valve assembly causes the assembly to dropdownwardly. The arms 131 pull the check valve downwardly since the valveis pivotally supported on the pins 133. As the valve seat body 110 dropsdownwardly pulling the arms and the check valve the pins 133 are movedin a downward direction relative to the pins 143 which remain fixedthrough the lower housing member. The check valve is rotated to theposition shown in H6. 2 due to the camming action of the pins in theslots 142. The outer spherical surface of the valve cooperating with theseat 112 shuts off fluid flow throughthe bore 111 of the valve seatbody. No pressure differential exists across the valve seat 110 due tothe bypass space between the seat and the member 32 and the sub 35.While it is evident from the position of the check valve in FIG. 2 thatthe valve has not rotated a full 90, the seat 112 is sufficiently incontact with the surface of the valve to shut off flow through the boreof the valve seat. The valve seat body is retained in the slightlyraised position illustrated by the spring engagedaround the valve seatengaging the ring of the collet 123 which rests on the upper end of thesub 35. The spring supports the valve seat body in an upward positionsufficiently to prevent contact of the seats 121 and 122 whereby fluidmay flow at a'low rate downward around the check valve seat body fromthe space between the safety valve and check valve. A downwardly actingpressure differential across the check valve and valve seat body will,however, move the valve seat downwardly against the resistance of thespring and cause the seats 121 and 122 to close off fluid flow throughthe bypass space around the valve seat body.

The safety valve will remain in closed position, as illustrated in FIG.2, until the pressures above and below the valve are substantiallyequalized. The equalizing of the pressures may be effected by pumpingfluid through the tubing string 11 into the well tool above the safetyvalve. Just before the pressure of the fluid being pumped in above thesafety valve reaches the value of the pressure below the safety valve,the coil spring 44 begins to move the safety valve seat body 41 in adownward direction to initiate the opening of the safety valve. Movementof the pins 65 downwardly relative to the pins 82 effects rotation ofthe ball safety valve toward open position. If the check valve werefully closed, the fluid trapped between the safety valve and check valvecould not be displaced and thus would prevent downward movement andopening of the safety valve. The spring 130 supports the faces 121 and122 apart from each other to enable the'fluid between the safety andcheck valves to be displaced downwardly around the check valve bodythereby allowing the safety valve assembly to move in a downwarddirection toward open position. The spring 130 is chosen with sufficientstrength to maintain the check valve seat in the upward position,illustrated in FIG. 2, against the downward flow of fluid from betweenthe valves to allow the safety valve to move to the position where itwill start opening. When the safety valve opens the pressuredifferential across the valve will equalize. Further pumping of fluiddownwardly may cause complete closing of the check valve assembly.Normally, however, the pumping of fluid downwardly will cease and thesurface valves will be opened to permit the well to flow again. Upwardflow will effect a pressure differential across the check valve whichwill move the check valve to open position. In opening the check valveseat body raises the pins 133 to effect rotation of the valve by thepins 143 acting in the slots 142.

Once the pressure on either side of the safety valve is equalized thecoil spring 44 around the safety valve seat body forces the bodydownwardly until the valve is again in full open position, asillustrated in FIG. 1. In the course of the opening of the valve theexternal recess 94 around the valve seat body will move downward untilthe balls 101 move inwardly into the recess from the surrounding recess93. When the recess 94 arrives opposite the recess 93 the force of thespring 103 acting downwardly through the spacer 102 and the cage againstthe balls causes the lower face of the recess 93 to cam the ballsinwardly into the recess 94 where the balls engage the lower surface ofthe recess. The force'of the spring 103 will then be added to the spring44 to bias the safety valve assembly to full open position'since theballs are again engaged with the upwardly facing bottom surface of therecess 94. With fluid flow once again occurring upwardly through thewell tool the check valve will be held in open position by a pressuredifferential across the valve and the safety valve will be held open bythe coil springs 44 and 103 until the fluid flow through the flow beanreaches such a rate that the pressure drop across the flow bean willagain exceed the predetermined limit to cause upward movement andclosing of the safety valve.

It will be readily apparent that the characteristics of the spring 44 ofthe safety valve assembly, the spring 103 of the detent assembly, andthe spring around the check valve seat body are chosen to satisfy theparticular requirements for which the well tool is designed. Aspreviously pointed out, in order to insure that the safety valve willnot linger between open and closed position the detent assembly requiresa somewhat greater force to actuate it and disengage the safety valveseat body than is actually required to then lift the body and close thesafety valve. The spring 103 is, therefore, chosen to require a somewhatgreater load to depress it than the spring 44. The effective forcerequired to depress the spring the force necessary to depress it asufficient distance to disengage the detent assembly. I

The spring 130 around the check valve seat body is chosen based on theforce required to'hold the body upwardly a sufficient distance to allowfluid to flow between the surfaces 121 and 122 while the safety valve ismoving downwardly toward open position. The spring must, however, bedepressable by the force resulting from fluid flowin excess of thatnecessary to allow opening of the safety valve so that higher flow rateswill completely close the check valve to permit it to fulfill itsfundamental function.

It will be readily recognized that while the well tool has beendescribed and illustrated as including both a safety valve and a checkvalve the safety valve assembly and its associated detent assembly maybe employed independent of the check valve assembly. For example, thecheck valve and its associated parts may readily be removed from thewell tool body by disengagement of the bottom sub 35 to allow the checkvalve seat body along with the check valve and the spring and colletassembly to be withdrawn as a unit from the lower housing member.

It will be seen that there has been described and illustrated a new andimproved well tool for controlling fluid flow in a well conductor whichis responsive to the fluid pressure within the conductor for controllingthe fluid flow therethrough.

It will also be seen that there has been provided a well tool includinga valve for a flow conductor wherein the valve is responsive to apredetermined fluid flow rate through the conductor.

It will be additionally seen that there has been provided a new andimproved pressure responsive device for controlling fluid flow through aconductor which includes a valve mechanism which is prevented fromassuming an intermediate position between open and closed positions tominimize erosion or abrasion of the valve parts by throttling of thefluid flow through the conductor.

It will be further seen that th e well tool includes a detent mechanismassociated with the safety valve to hold the valve tubing to release thedetent mechanism and thus free the valve to move to a fully closedposition.

It will also be seen that the well tool of the invention includes adetent mechanism which will hold a valve in fully open position andresist its being closed by temporary surges of fluid flow through aconductor.

It will also be seen that the'detent mechanism of the well tool detainsthe valve with which it is associated in an open position untilsufficient energy has been built up to move the valve to a fully closedposition without the valves lingering between such open and closedpositions.

It has also been shown that the detent mechanism employed with the welltool utilizes the ball-type locking elements between relatively movablemembers of tie tool to minimize the frictional forces involved.

It will be additionally seen that the well tool includes a spring loadedball-type valve element and a detentmechanism associated therewith whichalso includes a spring in the detent mechanism which is independent ofthe spring employed to retain the valve element in open position untilthe load from the fluid flow through the valve exceeds a predeterminedvalue in excess of the force required to depress the spring on the valveelement. I

It will also be seen that the well tool employs a safety valve and acheck valve which includes bypass means for allowing fluid to bedisplaced from between the valves around the check valve seat body topermit closing of the safety valve.

It will also be seen that the well tool includes in combination a safetyvalve with a detent mechanism and a fluid check valve.

Iclaim: V

l. A well tool including: housing means having a longitudinal flowpassage extending therethrough; upper valve seat body means slidablypositioned within said housing means, said body means having alongitudinal flow passage extending therethrough; ball valve meansrotatably supported on the lower end of said body means, said valvemeans having a flow passage therethrough to cooperate with said flowpassage through said body means when said valve means is in openposition; the lower end of said body means being provided with a valveseat for cooperating with said valve means to prevent fluid flow throughsaid well tool when said valve means is in closed position; said valvemeans being operably engaged with said housing means whereby movement ofsaid body means between extreme positions effects opening and closing ofsaid valve means by rotating said valve means about a transverse axis;spring means around said body means biasing said body means toward oneextreme position in which said valve means is open; detent means betweensaid body means and said housing means, said detent means being operablyengageable with said body means when said body means is in said extremeposition holding said valve means open, said detent means beingdisengageable from said body means in response to a force against saidbody means in excess of the force necessary to depress the spring meansaround said body means until said body means is moved to a secondextreme position in which said valve means is closed, said detent meansbiasing said body means toward said first extreme position when engagedwith said body means; lower valve seat body means having a longitudinalflow passage therethrough slidably positioned within said housing meansbelow said upper valve seat body means; second ball valve meanssupported on the upper end of said lower body means, said second ballvalve means having a passage therethrough for cooperating with saidpassage through said lower body means to permit fluid flow through saidwell tool; means interconnecting said second ball valve and said housingmeans for rotating said second ball valve between open and closedpositions by relative longitudinal motion between said lower seat bodymeans and said hous'ingmeans, said lower seat body means assuming adownward position effecting closure of said second ball valve connectedthereto when the fluid flow drops below a predetermined minimum throughsaid well tool; and means operatively associated with said housing meansand said lower seat body means for biasing said body means upwardly topermit fluid flow around said body means'between said body means andsaid housing means. v

2. A well tool for controlling fluid flow through a conductor including:a housing having a longitudinal passage therethrough; an upper ballvalve disposed in said passage and adapted to be moved between open andclosed positions; a spring operatively connected between said housingand said upper ball valve for biasing said ball valve toward openposition; means operatively associated with said ball valve foreffecting a pressure differential across said valve when fluid flow isoccuring through said valve; a detent assembly operatively engagedbetween said ball valve and said housing for retaining said ball valvein open position until the pressure differential across said valveexceeds a predetermined value which disengages said detent assembly topermit said pressure differential to actuate said ball valve towardclosed position; a lower ball valve disposed within said housing. belowsaid upper ball valve. said lower ball valve being operable between openand closed positions in response to fluid flow through said passage insaid housing, said second valve being biased toward open position byupward flow through said passage; check valve seat means movably securedwithin said longitudinal passage and engageable with said lower ballvalve for controlling fluid flow; and means operatively engaged betweensaid housing and said check valve seat means for biasing said lower ballvalve toward open position when downward flow around said lower ballvalveis below a predetermined rate I 3. A well tool for controllingfluid flow through a conductor: a housing having a flow passagetherethrough; an upper ball valve disposed in said housing and adaptedto move longitudinally between lower open and upper closed positions,said upper ball valve being biased toward open position and beingadapted to close in response to upward flow through said passage inexcess of a predetermined rate; a detent mechanism operably engagedbetween said housing and said upper ball valve for retaining said ballvalve in open position until the upward force on said ball valve exceedsthe downward bias on said valve by a predetermined value; a lower ballvalve disposed in said housing below said upper ball valve, said lowerball valve being movable between open and closed positions and beingbiased toward open position. by upward flow through said passage; checkvalve seat means movable longitudinally in said flow passage andengageable with said lower ball valve for controlling fluid flow throughsaid passage and means for biasing said lower ball valve and said checkvalve seat means toward open position for allowing downward flow aroundsaid lower ball valve below a predetermined minimum rate.

4. A well tool including: a housing having a longitudinal flow passageextending therethrough; a safety valve assembly disposed in said housingto shut off fluid flow through said passage when the fluid flow rateexceeds a predetermined value, means biasing said safety valve towardopen position; a detent assembly operatively engaged between saidhousing and said safety valve for detaining said safety valve in openposition until the closing force on said safety valve from fluid flowthrough said passage exceeds the biasing force on said valve by apredetermined value; a check valve assembly including a valve member anda seat member movably disposed in said flow passage, said check valveassembly being held in open position by fluid flow through said passagein one direction and moved to closed position by fluid flow through saidpassage in the other direction; and means operatively associated withsaid housing and said check valve seatmember for biasing said checkvalve assembly toward open position when the fluid flow rate tending to.close said check valve assembly is below a minimum value.

5. A valve assembly including: a housing having a longitudinal flowpassage; a safety valve mounted in said passage for movementlongitudinally and rotationally about a transverse axis in said housingbetween open and closed positions, said valve having a flow passage;means operatively connected to said valve and said housing wherebylongitudinal movement of said valve relative to said housing causesrotational movement of said valve within said housing; means operativelyassociated with said safety valve for effecting a pressure differentialin fluid flowing through said valve whereby a fluid flow rate in excessof a predetermined value biases said safety valve toward closedposition; means operatively engaged between said safety valve and saidhousing biasing said safety valve toward open position; detent meansengaged with said housing and operatively engageable with said safetyvalve to detain said valve in open position until the force tending toclose said valve exceeds the biasing force holding said valve in openposition by a predetermined value at which time said detent mechanismdisengages from said valve; a check valve assembly mounted in saidlongitudinal passage for movement longitudinally in said passage andincluding a longitudinally movable seat member and a valve memberengageable with said seat member and movable longitudinally androtationally about a transverse axis between open and closed positions,said check valve assembly having a flow passage; means operativelyconnecting said valve member and said housing whereby longitudinalmovement of said valve member relative to said housing causes rotationalmovement of said valve member within said housing; said check valveassembly being closable in response to fluid flow in a directionopposite to the direction in which said fluid closes said safety valve;and means for biasing said check. valve assembly toward an open positionto allow fluid flow past said valve member when the flow rate tendingtoclose said check valve assembly is below a minimum predetermined value.

6. A tool for controlling fluid flow includingzhousing means having alongitudinal flow passage extending therethrough; safety valve meanspositioned within said flow passage, said safety valve means beingbiased toward open position and being adapted to close in response to apressure differential across said safety valve in excess of apredetermined value; means operatively associated with said safety valvemeans and said housing means for retaining said safety valve means inopen position until a force tending to close said safety valve meansexceeds the force biasing said safety valve means toward open positionby a predetermined value; check valve means positioned in said flowpassage adjacent to said safety valve means, said check valve meansincluding a valve member and seat member movable longitudinally in saidflow passage and adapted to close in response to fluid flow opposite indirection to said flow tending to close said safety valve means; andmeans biasing said seat member of said check valve means longitudinallyof said flow passage to move said check valve means toward open positionto permit fluid flow past said means below a minimum flow rate.

7. A tool for controlling fluid flow including: housing means having alongitudinal flow passage extending therethrough; safety valve meanspositioned in said flow passage and adapted to close in response tofluid flow inexcess of a predetermined rate; means operatively connectedbetween said housing means and said safety valve means for biasing saidsafety valve means toward open position; means connected with saidhousing means and adapted to be connected with said safety valve meansfor detaining said safety valve means in open position until the fluidflow rate through said safety valve means exceeds a predetermined value;check valve means positioned within said flow passage upstream of saidsafety valve means, said check valve means including closure means andseat means movable in said'flow passage adapted'to close in response tofluid flow in an upstream direction; and means operatively connectedbetween said housing means and said seat means of said check valve meansfor biasing said seat means and closure means of said check valve meanstoward open position to permit fluid flow below a minimum fluid flowrate to allow drainage of fluid from between said safety valve means andsaid check valve means when opening said safety valve means subsequentto.closure.

8. A tool for controlling fluid flow including: housing means having alongitudinal flow passage extending therethrough; ball-type safety valvemeans positioned in said flow passage and adapted to close in responseto fluid flow through said passage in excess of a predetermined rate,said safety valve means including means for effecting a fluid pressuredifferential across said valve means; means operatively connectedbetween said safety valve means and said housing means for biasing saidsafety valve means toward open posi tion; means engaged within said flowpassage in said housing means and engageable with said safety valvemeans for detain-.-

ing said safety valve means in open position untilthe fluid flow ratethrough said flow passage exceeds the force biasing said safety valvemeans toward open position by a predetermined value; check valve meansincluding closure means and seat means positioned within said flowpassage and movable longitudinally within said flow passage on the sideof said safety valve means toward the source of fluid flow which closessaid safety valve means; and biasing means operatively connected betweensaid housing means and said seat means of said check valve means forbiasing said seat means and closure means of said check valve meanstoward said safety valve means to per mit a minimum fluid flow past saidcheck valve means to allow fluid trapped between said safety valve meansand said check valve means when both of said valve means are closed tobe displaced past said check valve means uponsubsequent opening of saidsafety valve means.

9. A tool for controlling fluid flow in a well including: a housinghaving a longitudinal therethrough; a safety valve seat body having alongitudinal flow passage slidably positioned within said flow passageof said housing; a ball-type safety valve rotatably secured on the lowerend of said seat body, said safety valve being rotatable about an axistransverse to the longitudinal axis of said housing and having a flowpassage therethrough to communicate with said flow passages of saidhousing and said safety valve seat body when said safety valve is inopen position; the lower end of said safety valve seat body having aface adapted to cooperate with said ball safety valve for shutting offfluid flow through said tool when said flow passage through said safetyvalve is not in communication with said flow passages through saidhousing and said safety valve body; fluid flow restriction means securedwithin said flow passage through said safety valve body; means connectedbetween said safety valve body and said housing for biasing said safetyvalve toward open position, said biasing means being adapted to holdsaid safety valve in open position when the fluid flow rate through saidvalve is below a minimum predetermined value; detent means connected tosaid housing around said safety valve seat body and engageable with saidbody for holding said safety valve in open position until the fluid flowrate through said safety valve exceeds by a predetermined value theforce biasing said safety valve toward open position; a check valve bodyhaving a longitudinal flow passage extending therethrough slidablyp'ositioned within said flow passage through said housing below saidsafety valve; a ball-type check valve rotatably secured on the upper endof said check valve body and adapted 'to rotate about an axis transverseto the longitudinal axis of said housing, said check valve having a flowpassage therethrough to communicate with said flow passage through saidcheck valve body to permit fluid flow through said tool; the upper endof said check valve body having a seat surface adapted to cooperate withthe surface of said check valve to prevent fluid flow through said checkvalve when said check valve is rotated to a position where the flowpassage through said'check valve is not in communication with the flowpassage through said body; and means biasing said check valve bodytoward said safety valve to allow a minimum fluid flow past said checkvalve body from between said check valve and said safety valve duringopening of said safety valve.

flow passage extending 10. A fluid flow control assembly including: ahousing havdinal axis of said'housing; a valve seat movably positionedwithin said flow passage, said valve seat being provided with a flowpassage communicating with said flow passage of said housing; a flowbean secured within said flow passage of said valve seat for effecting apressure differential across said valve seat responsive to fluid flowthrough said flow passage in said valve seat; a ball valve rotatablysecured to one end of said valve seat along an axis transverse to thelongitudinal axis of said flow passage through said housing, said ballvalve having a flow passage therethrough adapted to communicate withsaid flow passage through said valve seat when said ball valve is inopen position; the'end of said valve seat adjacent to said ballvalvehaving a seat surface adapted to cooperate with the surface of saidball valve for preventing fluid flow through said flow passage in saidvalve seat whensaid ball valve is in closed position; meansinterconnecting said ball valve and said housing for rotating said ballvalve between open and closed positions responsive to longitudinalmovement of said valve seat within said housing; a spring positionedaround said valve seat and engaged between said valve seat and saidhousing biasing said valve seat in a direction to urge said ball valvetoward open position; means secured within said housing around saidvalve seat for releasably engaging said valve seat to hold said ballvalve in open position until the pressure differential effected by saidflow bean exceeds a predetermined value; a second valve seat movablypositioned within said housing adjacent to and spaced apart from saidball valve on said first mentioned valve seat, said second valve seathaving a fluid flow passage extending therethrough communicating withsaid fluid flow passage through said housing; a second ball valverotatably secured to the end of said second valve seat adjacent to saidflrst mentioned ball valve along an axis extending transverse to thelongitudinal axis through said housing, said second ball valve having afluid flow passage therethrough communicating with said flow passagethrough said second valve seat when said ball valve is in open position;the end of said second valve seat adjacent to said second ball valvehaving a seat surface engageable with the surface of said second ballvalvefor preventing fluid flow through said second valve seat when saidball valve is in closed position; means interconnecting said second ballvalve and said housing for effecting rotation of said ball valve betweenclosed and open positions responsive to longitudinal movement of saidsecond valve seat relative to said housing; said second valve seat andsaid housing having cooperating surfaces adapted to control fluid flowaround said valve seat within said housing; and means engaged betweensaid second valve seat and said housing biasing said cooperatingsurfaces apart to permit fluid flow below a predetermined rate aroundsaid second valve seat from between said second valve seat and saidfirst mentioned valve seat.

11. A tool for controlling fluid flow including: a housing having a flowpassage extending therethrough along the longitudinal axis of saidhousing; a safety valve seat movably secured within said flow passage ofsaid housing, said safety valve seat having a longitudinal flow passagetherethrough communicating with the flow passage of said housing; a flowbean secured within the flow passage through said safety valve seat foreffecting a pressure differential in fluid flowing through said flowpassage; a ball safety valve rotatably secured on the lower end of saidsafety valve seat along an axis transverse to the longitudinal axis ofsaid seat, said valve having a flow passage therethrough adapted tocooperate with said flow passage through said seat to permit fluid flowthrough said safety valve; the lower end of said valve seat having aface thereon to cooperate with the surface of said safety valve tocontrol flow therethrough; means operatively connecting said safetyvalve and said housing whereby longitudinal movement of said safetyvalve seat relative to said housing effects rotation of said safetyvalve between open and closed positions; first spring means engaged atone end with said housing and at the other end with said safety valveseat for biasing said seat downwardly to open said safety valve; secondspring means operatively engaged at one end with said housing and engageable at the other end with said safety valve seat for retaining saidsafety valve in closed position until the. force of a pressuredifferential resulting from fluid flow throughsaid safety valve exceedsthe biasing force of said first Espring means, bya, predeterminedamount; a check valve seat movably positioned within said housing belowsaid safetytvalve, said check valve seat having a longitudinal flowpassage extending therethrough; a ball check valve rotatably engageablewith the upper end of said check valve seat on an axis transverse tosaid longitudinal flow passage through said check valve seat; said ballcheck valve having a flow passage adapted to cooperate with said flowpassage through said check valve seat when said ball check valve is inopen position to permit fluid flow through said tool; the upper end ofsaid check valve seat having a face thereon adapted to cooperate withsaid ball check valve for controlling fluid flow through said ball checkvalve; means operatively connecting said ball check valve with saidhousing whereby longitudinal movementof said check valve seat relativeto said housing effects rotation of said ballcheck valve between openand closed positions; said check valve seat having an external annularsurface adapted to cooperate with an internal annular surface withinsaid housing for controlling fluid flow along the outer surface of saidcheck valve seat within saidrhousing; and spring means engaged betweensaid check valve seat and said housing for biasing said seat in anupward direction whereby. said annular surfaces are held in spaced apartrelationship until fluid flow downwardly around said check valve seatfrom between said ball safety valve and said ball check valve exceeds apredetermined rate.

12. A tool for controlling fluid flow including: a housing having alongitudinal flow passage extending therethrough; a safety valve seatmovably positioned within said flow passage; said safety valve seathaving a longitudinal flow passage extending therethrough incommunication with said flow passage through said housing, the lower endof said safety valve seat having an annular face thereon adapted tocooperate with a ball-type valve for controlling fluid flow through saidsafety valve seat; a flow bean secured within said safety valve seat foreffecting a pressure differential within fluid flowing through saidseat; arm means engaged around said safety valve seat and extendingdownwardly from the lower end thereof; a ball safety valve rotatablysecured to said arm means along an axis extending transverse to saidpassage through said housing; said ball safety valve having a fluid flowpassage therethrough adapted to cooperate with said flow passage throughsaid valve seat to permit fluid flow through said tool; means engagedbetween said housing and said ball safety valve whereby longitudinalmovement of said safety valve seat effects rotation of said ball safetyvalve between open and closed positions; a first coil springpositionedaround said safety valve seat within said passage through said housing,the upper end of said coil spring being engageable with said housing andthe lower end of said spring being engageable with said safety valveseat whereby said safety valveseat is biased downwardly to effectrotation of said ball safety valve toward open position; a second coilspring positioned around said safety valve seat within said housing, theupper end of said second coil spring being engageable with said housing;annular locking means disposed within said housing around said safetyvalve seat below said second coil spring and engageable with the lowerend of said second coil spring; said safety valve seat being providedwith an annular external groove located to be engaged by said lockingmeans for releasably locking said safety valve seat in a downwardposition whereby said ball safety valve is held in open position untilthe pressure differential across said safety valve seat exceeds apredetermined value; said housing having an internal annular groove forreceiving said locking means when said locking means is disengaged fromsaid safety valve seat; a check valve seat movably secured within saidflow passage through said housing below said safety valve, said checkvalve seat having a longitudinal flo'w passage extending therethrough tocommunicate with said flow passage through said housing for permittingfluid flow through said tool, the upper end of said check valve seathavingjan annular face adapted to cooperate with a ball valve forcontrolling fluid flow through said passage in said check valve seat;arm means engaged on said check valve seat and extending upwardlytherefrom; a ball check valve rotatably secured to said arm means torotate about an axis extending transverse to the flow passage throughsaid housing, said check valve having a flow passage therethroughadapted to cooperate with said flow passage through said check valveseat to permit fluid flow through said tool; means engaged between saidhousingand said ball check valve for rotating said ball check valve inresponse to longitudinal movement of said check'valve seat relative tosaid housing whereby said ball check valve is rotated about its axisbetween open and closed' positions; said housing being provided with aninternal annular flange between said ball safety valve and said ballcheck valve, said flange having an upper face and a lower face adaptedto be contacted by and limit, respectively, the downward movement ofsaid safety valve and the upward movement of said check valve; saidcheck valve seat being provided with an external annular surface adaptedto cooperate with an internal annular surface provided within saidhousing to control fluid flow within said housing around said checkvalve seat whereby any fluid trapped between said safety valve and saidcheck valve when each of said valves is closed may be displaced aroundsaid check valve seat when said check valve is in closed position andsaid safety valve is being urged toward open position; and springlmeansengaged between said housing and said check valve seat for biasing saidcheck valve seat toward said safety valve to maintain a spaced apartrelationship between said annular surface around said check valve seatand said annular surface within said housing when the fluid flow aroundsaid check valve seat is below a predetermined rate.

13. A tool'for controlling fluid flow including: a housing having alongitudinal passage having a longitudinal axis; a safety valve seatmovably engaged within said passage through said housing, said safetyvalve seat having a passage having a longitudinal axis adapted tocooperate with said passage through said housing for permitting fluidflow through said tool, the lowerend of said safety valve seat beingprovided with an annular valve face adapted to cooperate with a ballvalve for controlling fluid flow through said passage through said seat;a flow bean secured within said flow passage within said safety valveseat for effecting a pressure differential in fluid flowing through saidseat; arm means engaged around said safety valve seat and extendingdownwardly therefrom; a ball safety valve rotatably secured to said armmeans along an axis extending transverseto the longitudinal axis throughsaid housing; said ball safety valve being provided with a flow passagetherethrough to cooperate with said flow passage through said safetyvalve seat for controlling fluid flow through said safety valve; saidball safety valve being provided with external slots on opposite sidesthereof, the center line of second coil spring; a plurality of ballshaped locking elements carried by said cage; the upper end of said cagebeing urged downwardly by said second coil spring; said safety valveseat being provided with an external annular recess for receiving saidball shaped locking elements to releasably lock said safety valve seatin a downward positionvwhereby said safety valve is held in openposition until the fluid rate through said valve exceeds a predeterminedvalue in excess of the biasing force of said first mentioned coilspring; said, housing being provided with an internal annular recessadapted to receive said ball shaped locking elements when said elementsare disengaged from said safety valve seat; a check valve seat movablypositioned within said flow passage through said housing below saidsafety valve, said check valve seat having a flow passage extendinglongitudinally thereof to provide communication with said flow passagethrough said housing, the upper end of said check valve seat beingprovided with a spherical annular face adapted to cooperate with a ballshaped valve for conmeans extending through said housing engaging'said.slots in l said ball check valve whereby longitudinal movement of saidcheck valve seat causes said pin means to rotate said ball check valvebetween open and closed positions; said check valve seat being providedwith a downwardly facing external annular face to cooperate with anupwardly facing internal annular face within said flow passage throughsaid housing for controlling fluid flow within said housing around saidcheck valve seat; a coil spring disposed within said flow passage aroundsaid check valve seat, said coil spring being engageable with saidhousing at the lower end thereof to bias said check valve seat in anupward direction to maintain a spaced relationship between said annularface around said check valve seat and said annular face within said flowpassage through said housing whereby fluidtrapped between said checkvalve and said safety valve may be displaced around said check valveseat when said check valve is closed and said safety valve is beingmoved downwardly when the fluid flow is around said valve seat exceeds apredetermined limit; and an internal aneach of said slots beingcoincident with a line intersecting the axis of rotation of said ballsafety valve; pin means secured through said' housing engaging saidslots of said safety valvewhereby longitudinal movement of said safetyvalve seat relative to said housing effects movement of said pin meansin said slots to rotate said ball safety valve between open and closedpositions; a first coil spring disposed within said flow passage throughsaid housing around said safety valve seat, said coil spring beingengaged with said housing at the upper end thereof and secured to saidsafety valve seat at the lower end thereof whereby said safety valveseat is biased downwardly to urge said ball safety valve toward openposition; a second coil spring disposed around said safety valve seatwithin said flow passage through said housing, said spring beingengageable at the upper end thereof with said housing; an annular cagehaving a plurality of radially spaced holes therethrough positionedaround said safety valve seat within said housing below said nularflange formed within said housing between said safety said check valveseat body engaged with the lower end of said coil spring, said colletring having upwardly extending fingers provided with inwardly projectingbosses, said inwardly projecting bosses engaging said second externalannular flange for supporting the lower end of said coil spring fromsaid flange;

and said external annular flanges and said collet ring being so spacedto maintain said annular face around said check valve seat and saidannular face within said housing in a spaced apart relationship whensaid collet bosses are engaged with the upper surface of said secondexternal annular flange.

15. A tool for controlling fluid flow including: housing means having alongitudinal flow passage extending therethrough; safety valve meanspositioned within said flow passage and biased toward open position;said safety valve means being adapted to close in response to a fluidpressure differential across said valve means in excess of apredetermined value; and means operatively associated with said safetyvalve means and said housing means for retaining said safety valve meansin open position until a force effected by a pressure differentialacross said safety valve means tending to close said safety valve meansexceeds by a predetermined value the force biasing said safety valvemeans toward open position; check valve means positioned in said flowpassage adjacent to said safety valvemeans, said check valve meansincluding a valve member and seat member movable longitudinally in saidflow passage and adapted to close in response to fluid flow opposite indirection to said flow tending to close said safety valve means; andmeans biasing said seat member of said check valve means longitudinallyof said flow passage to move said check valve means toward open positionto permit fluid flow past said means below a minimum flow rate.

16. A tool for controlling fluid flow including: a housing having alongitudinal flow passage having a longitudinal axis; a check valve seatmovably secured within said flow passage through said housing, saidcheck valve seat having a longitudinal flow passage extendingtherethrough to communicate with said flow passage through said housing,the upper end of said check valve seat being provided with an annularface adapted to cooperate with a ballvalve for controlling fluid flowthrough said passage in said valve seat; arm means engaged on said checkvalve seat and extending outwardly therefrom; a ball check valverotatably secured to said arm means to rotate about an axis extendingtransverse to the flow passage through said valve seat, said ball checkvalve having a flow passage therethrough adapted to cooperate with saidflow passage through said valve seat; means engaged between said housingand said ball check valve for rotating said ball check valve in responseto longitudinal movement of said check valve seat relative to saidhousing whereby said ball check valve is rotated about its axis betweenopen and closed positions; means providing a bypass flow passage aroundsaid check valve seat within said housing; and means engaged betweensaid housing and said check valve seat biasing said check valve seat ina direction to permit fluid flow through said bypass flow passage whenthe fluid flow rate through said tool tending to close said check valveis below a predetermined value.

17. A check valve for use in a well conduit including: a housing havinga longitudinal flow passage therethrough; a valve seat movablypositioned within said flow passage through said housing, said valveseat having a flow passage extending longitudinally thereof to providecommunication with said flow passage through said housing, the upper endof said valve seat being provided with a spherical annular face adaptedto cooperate with a ball shaped valve for controlling fluid flow throughsaid flow passage through said seat; arm means engaged around said valveseat and extending outwardly therefrom; a ball check valve rotatablysecured to said arm means along an axis'extending transverse to the axisof said flow passage through said valve seat; said ball check valvehaving slots on opposite sides thereof, the center line of each of saidslots being coincident with a line intersecting the axis of rotation ofsaid ball'check valve; pin means extending through said housing andengaging said slots in said ball check valve whereby longitudinalmovement of said check valve seat causes said pin means to rotate aboutsaid ball check valve between open and closed positions; said valve seatbeing provided with an external annular face adapted to cooperate withan internal annular face formed within said housing for controllingfluid flow within said housing around said valve seat; said valve seatand said housing being sized to provide space therebetween to form abypass around said valve seat; and a coil spring disposed in said flowpassage around said valve seat, said coil spring being engageable withsaid housing at one end thereof and with said valve seat at the otherend thereof to bias said valve seat toward said ball check valve tomaintain said annular face around said valve seat and said annular seatwithin said housing in a spaced apartrelationship until the fluid flowrate past said ball check valve around said valve seat through said byass exceeds apredetermined value. v

18. tool or controlling fluid flow including: 'housing means having alongitudinal flow passage extending therethrough; safety valve meansposition'ed withi'n said flow passage and biased toward open position;said safety valve means being adapted to close in response to a fluidpressure differential across said safety valve means in excess of apredetermined value; means operatively associated with said safety valvemeans and said housing means for retaining said safety valve means inopen position until a force effected by a pressure differential acrosssaid safety valve means tending to close said safety valve means exceedsby a predetermined value the force biasing said safety valve meanstoward open position; and check valve means including a valve closuremember and valve seat means comprising a tubular seat member engageablewith said closure membervand movable longitudinally between open andclosed positions in said flow passage in said housing spaced from saidsafety valve means and responsive to fluid flow in a reverse directionthrough said housing to close off flow therethrough, and means biasingsaid tubular seat member of said check valve means toward open positionto permit fluid flow around said check valve means below a minimum flowrate. v

19. A tool for controlling fluid flow including: housing means having alongitudinal flow passage extending therethrough; ball-type safety valvemeans positioned in said flow passage, said safety valve means includingmeans for effecting a pressure differential across said safety valvemeans to move said safety valve means to closed position in response tofluid flow through said flow passage in excess of a predetermined rate;means operatively connected between said safety valve means and saidhousing means biasing said safety valve means toward open position;means engaged within said flow passage through said housing means andengageable with said safety valve means for detaining said safety valvemeans in open position until the pressure differential across saidsafety valve means in response to the flow through said safety valvemeans effects a force in excess of the force biasing said safety valvemeans toward open position by a predetermined value; and check valvemeans including a valve closure member and a seat means coactingtherewith and movable longitudinally in said flow passage in saidhousing normally open to permit flow in one direction through saidhousing and movable responsive to reverse flow at a rate above apredetermined rate to shut off flow in said reverse direction throughsaid housing.

20. A well tool for controlling fluid flow through a conductorincluding: a housing having a longitudinal flow passage therethrough;first valve means positioned in said flow passage and movable betweenopen and closed positions therein and biased toward open position andmovable by pressure of fluids flowing through said housing to closedposition when the pressure of said fluids exceeds a predetermined value;second valve means including a valve closure member and a seat membermovable longitudinally in said flow passage in said housing spaced fromsaid first valve means; said seat member normally biased open andmovable in response to pressure of fluid flowing through said housingand coacting with said closure member for controlling flow in a reversedirection

